hermann



l. W. HERMANN.

AUTOMATIC IMPULSE STARTER.

APPLICATION mm NOV. 9. ms.

1,318,206. Patented 0m. 7,1919.

- 2 SHEETS-SHEET l.

J. W. HERMANN.,

Patented Oct. 7,1919.

2 SHEETS-SHEET 2.

AUTOMATIC IMPULSE STARTER.

APPLICATION FILED NOV. 9. ms.

UNITED STATES PATENT OFFICE.

JOSEPH WOLFGANG HERMANN, OF CHICAGO, ILLINOIS, ASSIGNOR TO SPLITDORF ELECTRICAL CO., OF NEWARK, NEW JERSEY, CORPORATION OF NEW JERF.

SEY.

AUTOMATIC IMPULSE-STARTER.

Patented Oct. '7, 1919.

Application filed November 9, 1916. Serial No. 130.439.

To all whom it may concern.

Be it known that I, JOSEPH WOLFGANG HERMANN, a citizen of the United States, re-

siding at Chicago, in the county of Cook and State of Illinois, have invented certain new, and useful Improvements in Automatic Impulse-Starters, of which'the following is a specification;

The employment of magnetos isnow regarded as the most satisfactory method ofproducing the requisite electrical current for the ignition of internal combustion engines, but it is necessary to operate the ordinary rotating magnetos at a fairly high speed before they reach the point of efliciency at which the current output is sufiicient. for

producing adequate sparking. For this reason difficulties arise when starting internal combustion engines equipped with rotating magnetos, due to their failure to produce suflicient current under the slow starting speed of the motors in turning them over the point of compression. Batteryland coil ignition, as a source for starting internal combustion engines, has been relied on, but this involves additional expense for the battery, coil, switch, wires and their installa tion; it makes the ignition outfit more complicated, and increases the cost of maintenance. Batteries are also .apt to give out and a loss of time results in obtaining new ones. Eflort also has been made to equip rotating magnetos with various mechanism whereby .to obtain accelerated movements of the magneto armature or rotor when starting the engine. Some of these must be manually operated to condition the magneto armature or rotor for accelerated movements, and thus are open to uncertainty of operation due to the necessity for manual setting. Others are automatic but the latter have the disadvantage that they cut out the accelerated movement of the magneto armature or rotor at a certain speed, and as soon-as the engine slows down to this same speed the accelerated movements of the magneto armature or rotor will begin again'automatically. It is necessary that the speed, at which the accelerated movements of the magneto armature or rotor should be cut 0ut,be a ve high one; it must be much higher than the speed necessary to drive the magneto fast adequate spar der the motor and magneto speed will rise to a maximum, and from there will drop down to a minimum until the second explosion occurs. The minimum speed after the second explosion, and just before the third explosion, will be a higher one than it was previously before the second explosion. After a series of explosions the minimum speed of the motor and the magneto armature or rotor will finally reach the point at which the magneto speed will be sufficient to generate enough current for adequate sparking. The difference between the maxithis would cause only unnecessary wear on the operating parts. As explained before a variable maximum speed is necessary to obtain this minimum speed, so that a fully automatic device for accelerated movements of the magneto armature or rotor must cut out the accelerated movements at a higher speed than is necessary to permit them. It must also provide means for adjustment to condition itself for the variable maximum speed of the different engines on which used, and at which speed the accelerated movements of the magneto armature or rotor should be cut out.

The present invention aims to provide mechanism for overcoming the objections noted, to which end it is proposed to equip a magneto with simple and efficient means whereby under itsslowest speed the same automatically will condition itself for a series of accelerated movements of its armature or rotor and thereby produce an effective ignition spark.

The invention also contemplates an adjustable structure which, on the engine attaining the proper speed for operation of the magneto, will be thrown out of operation automatically andretained therein during the synchronized movement of the magneto and engine.

The invention also aims to provide means I by. which on the engine slowing down to a speed at which the magneto generates insufficient current to produce an effective spark, a structure will be thrown in auto matically for efl'ecting again the accelerated movements of the magneto armature or rotor. I

A further object of the present invention I is the provisio'n of a device of the character mentioned'wherein the operative arts are reduced to a minimum and are so re ated and cotirdinated as to occupy but little, space, 'be

cheaply manufactured and be readily accessible'for removal or repairs when inspection or replacement is necessary. l

Other objects and advantages will become apparent as the nature of the improvements is better understood, the invention consist- .ing in the novel construction, combination and arrangement of parts hereinafter fully- -described, illustrated in the accompanying drawings, and finally pointed out in the appended claims.

While the invention is depicted in the accompanying drawings in its preferred embodiment, it will be understood that such embodiment is but oneadaptation thereof,

so that the invention is not to be restricted to the form illustrated and described. In the drawings: i

're 1 is an elevation of-an automatic .impu se starter constructed in accordance with the present invention.

Fig. 2 is a side elevation thereof;

' Fig. 3 is a view similar to Fig. 1, 'illus trating the parts in a difierent position.

Fig. 4 is a vertical transverse sectiona view on the line 4=4, Fig. 1.

Figs. 5 and 6 are end elevations illus-I trating the parts in further difi'erent positions from the positions illustrated in Figs: 1 and 3.

Fig. 7 is a detail elevation of the accelerating disk, parts being in section'as on the line 7-7, Fig. 4.

Fig. 8 is a vertical section on the line 8-8, Fig. 4, illustrating the centrifugally acting pawl carried by the accelerating disk.

Fig. 9 is a detail sectional view illustrating the manner of mounting the pivot studs for the locking pawl.

Referring in detail to the accompanying drawings, the numeral 1 designates the casing of a magneto, which may be of any approved construction, and 2 its armature shaft. The parts of the hereindescribed impulse starter are, in the main, carried by the armature shaft 2, and to this end said-shaft isprovided with a taperedv portion 3 terminating in a screw-threaded neck 4' on whichis-mounted a securing nut 5 for holding the parts in position upon the shaft 2. Keyed to the shaft 2 is an accelerating disk 6 which has a tapered bore to fit the tapered portion 3 of said shaft. The disk 6 is thus rmly held for rotation with said shaft. At

one-face of the disk 6, and surrounding the bore thereof, is a' hub 7, and surrounding said hub is a concentric chamber 8', about which chamber is an annular flange 9. A driving member 10, which is in the form of a cap, fits overv the disk 6 so as to cover thechamber 8 thereof, and said member 10 has an inwardly-extending annular flange 11 which fits u on the hub 7 of the disk 6, said member 10 a so'having an annular flange 12 at its periphery which fitsupon the flange 9 of the disk 6. Between the flanges 11 and 12 of the member 10 is formed an annular. recess which lies opposite to the chamber 8 when the parts are assembled. The flanges 11 and 12 of the driving member 10 are adapted for rotatable movement on the hub 7 and the -flange 9 of the accelerating disk 6, thereby enabling the driving member tohave relative movement with respect to said disk, as will bepresently explained.

A'washer 14 surrounds the neck 4 and is interposed between the nut 5 and the driving carried. by the member 10. Between the studs 16 and 17 is also arranged a hufier spring 18. The pressure ofthe spring 15 is such that under normal conditions of operation the disk 6 will be actuated b the driving member 10 without any relative movement -between'the two parts. When, however, the movement of the disk 6 is impeded the spring 15 becomes compressed to a greater degree, by reason of the stud 17 approaching the stud 16, and it is this compression of the spring 15 which provides for the accelerated movement of the disk 6.

The peripheral faceof-the disk 6 is provided with one or more notches 19. Two of these are shown in the drawings and are arranged diametrically opposite to each other. One :wall of each of the notches 19 is abruptto form a shoulder 20, while the other wall is inclined, as at 21, and the face of the disk,

adjacent to each of the shoulders is also slightly inclined as at 22. Pivoted on a screw stud 23 is a locking pawl 24, the screw stud 23 being carried by a supporting plate 25 adapted to be held upon the magneto casing 1 by ineans of screws 26, or their equivalent. This supporting plate 25'is also provided with a centrally-disposed aperture 27 of suitable configuration to fit over the armature shaft of the spring 34 is to throw the arm 28 to.

v of that notch.

thereby hold the locking pawl 24 in the plane of the accelerating disk 26. The pawl 24 is provided with an upwardly-extending arm 28, said arm being bifurcated, as at 29, for the reception of the head 30 of a stem 31. The stem 31 is pivoted within the bifurcation 29 by a pin 32, the upper. end of the stem 31 passingv through'a countersunk perforated lug 33, and surrounding said stem 31, and interposed between the head .30 and the lug 33, is a coil spring 34. The function either side of a central line between the lug 33 and the screw stud 23. The arm 28 and the stem 31 constitute a toggle joint and said spring 34' serves to hold the pawl 24 in either elevated or lowered position, as will presently appear.

The pawl 24 is adapted to lock the accelerating disk 6 against movement, and in accomplishing this the free end of said pawl enters one of the notches 19 and abuts against the shoulder 20 thereof. The free' end of the pawl 24 is provided with an upper contact face 35 and a lower contact face 36, said faces extending in divergent relation to each other, so that when the pawl 24 enters one of the notches 19 the upper contact face 35 abuts squarely against the shoulder 20 This engagement is clearly shown in Fig. 3, in which position the pawl is held by-the spring 34 exerting its pres sure against the arm 28. Under proper speed of rotation the lower contact face 36 of the pawl 24 rides over the inclined sur-. faces 22 of the disk 6, and this effects the kicking out of the pawl 24 to permit continuous rotation of the disk 6 with the driving member 10.

At the under side of the pawl 24 is pro.- vided a transversely extending abutment 37 which is adapted to be engaged by the nose 38 of a setting pawl 39 pivoted at 40 to the inner face of the accelerating disk 6. The

pivot 40 is so positioned that the weight of the pawl 39 below said pivot will greatly preponderate over that portion of the pawl above the pivot. This causes the nose of the pawl to project beyond the peripheral face of the disk .6, when the pawl hangs substantially vertically, as illustrated 1n Fig. 1, and when in this position it will be seen that the nose'38 of the pawl'is projected sufficiently for contact with the abutment 37 as the disk 6 rotates. On such contact being made the pawl 24 will be thrown downwardly toward the disk 6, and held in such position by the spring 34, as previously explained. By mounting the setting pawl 39 in the manner noted it will also be obvious that the same will swing outwardly under the rotation of the disk 6, and for limiting such outward movement a slot 41 is formed in the pawl 39, said slot receiving a stud 42. The

setting-pawl 39 has a notch 43 so that as said pawl 39 is swung outwardly under-centrifugal force this notch 43 will register with the adjacent notch and prevent contact of the pawl 39 with the locking pawl when the latter is about to occupy one of .the'

notches 19.

As. it may besometimesdesirable to reverse the position of the pawl 24, a screw stud 44 similar to the stud 23 is provided at the opposite side of the slot 27 to that at which the stud 23' is located. A spacing washer 45 surrounds said stud 44, and connecting the latter and the stud 23 is aspacing bar 46. The bar 46 ties the studs 23 and 44 together and also braces the same.

These studs are threaded into the plate 25 by reduced extensions and the bodies of the studs are received by counterbores formed in the plate 25, as shown in Fig 9, thereby rigidly holding the studs on saldplate. A'

perforated lug 47, similar to the lug. 33, is

also provided above the screw stud 44, said lug 47 receiving the. stem 31 when the latter has been transferred to'the side of the plate 25 at which said lug 47 is located.

By countersinking the lugs 33 and 47 the up per end of the stem 31 has freedom of movement as it oscillates during the throwing of the pawl 24.

Stops 48 are also provided on the supporting plate '25 to limit the throw of the pawl 24. v

The driving member 10 is provided at diametrically opposite points with cams 49, which cams extend outwardly" from the driving member 10 so'that their peripheral faces will lie in substantially the same plane with the peripheral face of the accelerating disk 6. As the driving member moves relatively to the accelerating disk, when the latter is locked against movement 'by the pawl 24 engaging one of the notches 19, one

and wipe under .the pawl 24. The width of the pawl 24 is greater than the width of the accelerating disk 6 so that portions of the pawl project beyond the side edges of said disk, and one of these projecting portions is in the path of movement of the cams .49. cam moves under the pawl 24, the latter will be lifted by the cam out of the notch 19 which it occupies, and when the pawl has cleared the shoulder 20, the compressed spring 15 gives to the disk 6 an accelerated movement so that the same is caused to overtake the driving member 10, and this imparts a quick movement to the armature- Therefore, as the approaching 24. The weight of the lower end 'of the pawl 39 maintains the latter'in this .position as the pawl rises upwardly during the rotation of the disk. The locking pawl 24 is sustained in its elevated position by reason of the spring 34 exerting its pressure at a point to the right hand side of a central line between the stud 23 and the lug 33. Assuming now that it is desired to start the engine, the latter is turned over, and thus slow rotation is imparted to the driving member 10, which rotation is communicated to the disk 6 through the spring 15. As the nose 38 of the pawl 39 strikes the abutment 37 the pawl 24 is swung downwardly onto the peripheral face of the disk 6, and as the approaching notch 19 moves up to the pawl 24 thefree end thereof is forced into the notch by the action of the spring 34 so that the upper contact face 35 of the pawl abuts against the shoulder 20. The position of the parts at this stage of the operation is shown in Fig. 3. The pawl 24 now locks the accelerating disk 6 against further forward movement, but the driving member 10 continues its forward rotation,

and in this movement the stud 17 carried ing disk follows. An accelerated movement to the armature or rotor shaft 3 is imparted, and a spark is produced. In the readjustment of the relation of the disk 6 and the driving member 10 after the disk is released in the manner described, the buffer spring 18 between the studs .16 and 17 serves to cushion the movement of the accelerating disk as it advances to its normal position with respect to the driving member 10. The position .of the parts when the cam 49 is about to release the pawl 24 is illustrated in Fig. 5.

After the pawl- 24 has been released un der the slow movement of the driving member 10 its free end will ride upon the peripheral face of the (113K 6, and if the speed of the driving member 10 does not materially increase the pawl will become seated in the succeeding notch 19, the cycle of movements above described following such engagement, and further sparking being effected. In this manner when the engine is operated in starting, and the parts are moving at their slow speed, the hereindescribed invention provides for the production of the necessary ignition spark. As

seated in the notches, but the contact face 36 will ride-over the inclined faces 22 of the disk, the speed becoming sufiiciently great tocause such an impact with the pawl 24 that the same will be thrown upwardly and the arm 28 and stem 31 swung beyond the dead center. The spring 34 then comes into play to sustain the pawl 24 in its elevated position, and the disk 6 and driving member 10 will then operate in synchronism with the engine. The position of the parts in the stage of operation just described will be seen from Fig. 6. While the magneto is speeding up the pawl 24 rides on the peripheral face of the disk 6, as described, and during this position it is desirable that the pawl shall not be thrown outwardly by contact of the setting pawl 39. To attain this the end of the nose 38 1s slightly inclined so that as it contacts .the face 36 of the pawl 24 said nose will ride under the latter without throwing the pawl outwardly.

From the foregoing it will be apparent that the herein described mechanism is fully automatic in its action, both in being set for the accelerated movement of the armature and in being thrown out of operation when the movement of the armature has been synchronized with the movement of the engine. So long as the driving member 10 and the accelerating disk 6 are working within the limit of their slow speed, which limit may be defined by any arbitrary speed that may be selected, the nose of the pawl 39 will always be projected beyond the pe ripheral face of the accelerating disk, and thus in position to actuate the pawl 24 so as to periodically lock the disk and obtain a succession of accelerations of the armature shaft. This is particularly true when the load on the engine is such as to reduce its speed below said limit of slow speed. \Vhen, however, such limit has been exceeded, the pawl 39, under centrifugal action, is freed from further engagement with the pawl 24, and when the armature shaft has become synchronized with the movement of the engine the pawl 34 will be kicked upwardly to the limit of its elevation and there sustained. The movement of the pawl 39 is governed by the weight of the same, and if it be desired to vary the limit of the slow speed under which said pawl actuates the pawl 24, it will be understood that the weight of the pawl will be varied, either by substituting a heavier or a lighter pawl, and thus varying the action of the pawl under centrifugal force. The speed at which thepawl 24 is kicked out and restored for contact by the pawl 39 also may be controlled by imparting different degrees of tension to the spring 34- or substituting springs. of different ten-v sion therefor. v

I claim:

1. In 'a device of the class described,the

combination with the rotor of a magneto, of a driving element for actuating the same, accelerating means associated-with said rotor and connecting the sameto said driving element, devices in proximity to said accelerating means for restraining the rotor, means for holding said devices in non-restraining position, independent means associated with said accelerating means for throwing said devices to restralning position, and means for releasing said devices to permit the accelerating means to actuate the rotor.

2. In a device of the class described, the combination with the armature shaft of a magneto and a driving member for actuating the same, connecting meansinterposed between said armature shaft and driving member including a spring normally of sufficient tension so that said drivingmember and armature shaft will rotate in the same timing, means for restraining the movement of the armature shaft for compressing and storing power in said spring and meansfor releaslng said restrainlng means whereb,

said spring may propel the armature sha momentarily at a greater speed than the driving member, means for automatically throwing said'restraining means into operative position when the armature shaft falls .below a predetermined speed.

3. In a device of the class described, the combination with the armature shaftofa magneto and a driving member for actuating the same, coniiectmg means interposed between said armature shaft and driving member including a spring normally of sufficient tension 'so that said driving member and armature shaft will rotate in the same timing, means for restraining the movement of the armature shaft for compressing and storing power in said spring and means for releasing said restraining means Whereb said spring may propel the armature sha said accelerating disk and the driving member, said spring being of suflicient tension so that the driving member and armature shaft normally turn in the same timing, said accelerating disk having a notch formed therein providing a shoulder, a restraining pawl adapted to .engage said shoulder for momentarily stopping the armature shaft for compressing said spring, means movable with the driving member for releasing said pawlafter said spring has been compressed, means for throwing said pawl out of operative position when the armature reaches a predetermined speed, and means fortmoving said pawl into operative position when the armature is ,moving below a predetermined speed.

5. In a device of the class described, the

combination with the rotor of'a magneto,

of a driving element for actuating the same, accelerating means associated with said rotor and connecting thesame to said driving element, said accelerating means including a spring of suflicient tension so that said driving element and rotor turn together in the same timing, a pawl pivoted in proximity to said accelerating means" for restraining the rotor and compressing said spring, a resilient toggle connect-ion for holding the pawl in restraining and-nonrestraining position, means for setting'said pawl in restraining position and means releasing said' pawl to permit accelerating movement of the rotor.

6. In. a device of the class described, the combination with the rotor of a magneto, of a driving element for actuating the same, accelerating'means associated with said rotor and connecting the same to said driving element, said accelerating means including a spring of suflicient tension so that said driving element and rotor turn together in the same t'timing, a pawl' pivoted in proximity to said accelerating means for restraining the rotor, means for holding the pawl in non-restraining position, an abutment carried by said pawl and means associated with said accelerating means for engaging said, abutment to throw the pawl to restraining position and means for releasing said pawl. to permit the acceleratmg movement of the rotor by the spring.

In a device of the class described, the

combination with the rotor of a magneto,

of a driving element for actuating the same, accelerating means associated with said rotor and connecting the same to said driving element, said accelerating means including a spring of suflicient tension so that said driving element and rotor turn together in the'same timing, a pawl pivoted in proximity to said accelerating means for restraining the rotor, means associated with said accelerating means for automatically setting said pawl in restraining position under slow speed of the rotor, said means being inactive in'relation to said pawl at a predetermined high speed of the rotor and means for releasing the pawl to permit ac-' celerated movement of the rotor by the spring.

8. In a device of the class described, the combination with the rotor of a magneto, of a driving element for actuating the same, accelerating means associated with said rotor and connecting the same to said driving element, said accelerating means including a spring of sufficient tension so that said driving element and rotor turn together in 'the same timing, a pawl pivoted in proximity to said accelerating means for re straining the rotor, means for holding said pawl in restraining and non-restraining positions, an abutment carried by. said pawl, a centrifugal acting setting member associated with. said accelerating means and adapted to engage said abutment at slow speed of the rotor to throw the pawl to restraining position, said setting member being inactive with respect to the pawl at a predetermined high speed of the rotor and means for releasing said pawl to permit accelerated movement of the rotor by the spring.

9. In a device of the class described, the combination with the rotor of a magneto, of a'driving element for actuating the same, accelerating means associated with said rotor and connecting the same to said driving element, said accelerating means including a spring of sufiicient tension so that said driving element and rotor turn together in the same timing, a .pawl pivoted in proximity to said accelerating means for restraining the rotor, a resilient toggle connection for holding said pawl in restraining and non-restraining positions, an abutment carried by said pawl, a centrifugal acting means associated with said accelerating means and adapted to engage said abutment under slow speed of said rotor for throwing said pawl to restraining position but inactive with respect to said pawl under predetermined high speed of said rotor and means associated with said driving element for releasing the said pawl "to permit accelerated movement of the rotor.

10. In a device of the class described, the combination with the rotor of a magneto, and a driving element for actuating the same, of accelerating means associated with said rotor, means for affording a normal driving connection between said accelerating means and said driving element but permitting relative movement therelbetween under predetermined conditions, a pawl pivoted in proximity to said accelerating means'for restraining the latter, a resilient toggle connection for holding said pawl in restraining and non-restraining position, means for setting said pawl in restraining position,

and means for releasing said pawl to permit accelerated movement of the rotor.

11. In a device of the class described, the combination with the rotor of a magneto, and a driving element for actuating the same, of accelerating means associated with said rotor, means for afiording a normal driving connection between said accelerating means and said driving element but permitting relative movement there-between .under predetermined conditions, a pawl pivoted in proximity to said accelerating means for restraining movement of the latter, means for holding said pawl in non-restraining position, an abutment carried by said pawl, means associated with said accelerating means for engaging said abutment to throw the pawl to restraining position, and means for releasing said pawl to permit accelerated movement of the rotor.

12. In a device of the class described, the combination with the rotor of a magneto, and a driving element for actuating the same, of acceleratingmeans associated with said rotor, means for aiiording a normal driving connection between said accelerating means and said driving element but permitting relative movement therebetween under predetermined conditions, a pawl pivoted in proximity to said accelerating means for restraining movement of said accelerating means, an abutment carried by said pawl, a setting pawl associated with said accelerating means and adapted to engage saidabutment to throw the pawl to restraining position, and means for releasing said pawl to permit accelerated movement of the rotor.

13. In a device of the class described, the combination with the rotor of a' magneto, and a driving element for actuating the same, of accelerating means associated with said rotor, means for aflording a normal driving connection between said accelerating means and said driving element but permitting relative movement therebetwec-n under predetermined conditions, a pawl pivoted in proximity to said accelerating means for restraining movement of the latter, means associated with said accelerating means for automatically setting said pawl in restraining position under slow speed of the rotor but inactive in relation to said pawl at a predetermined high speed of the rotor, and means for releasing said pawl to permit accelerated movement of the rotor.

14:. In a device of the class described, the combination with the rotor of a magneto, and a driving element for actuating the same, of accelerating means associated with said rotor, means for affording a normal driving connection between said accelerating means and said driving element but permitting relative movement therebetween under predetermined conditions, a pawl pivoted means and adapted to engage said abutment and a driving element for actuating the at slow speed of the rotor to throw the pawl to restraining position, but inactive with respect to said pawl at a predetermined high speed of the rotor, andmeans for releasing said pawl to permit accelerated movement of the rotor. 7

15. In a device of the class described, the combination with the rotor of a" magneto,

same, of accelerating means associated with said rotor, means for affording a normal driving connection between said accelerating means and said driving element but permitting relative movement therebetween under predetermined conditions, a pawl pivoted in proximity to said accelerating 'means for restraining movement of the latter, a resilient toggle connection for holding said pawl in restraining and non-restraining positions, an abutment carried by said pawl, a centrifu gally acting setting pawl associated with said accelerating means and adapted to engage said abutment under slow speed of said rotor for throwing said pawl to restraining position, but inactive with respect to said pawl under predetermined .high speed of said rotor, and mean'skassociated with said drivingelement for releasing said pawl to permit accelerated move-- ment of the rotor.

16. In a device of the class described, the combination with the rotor of a magneto, and a driving element for actuating the same, of an accelerating disk associated with said rotor, means for affording a normal driving connection between said accelerating disk and said driving element but permit;

ting relative movement therebetween under predetermined conditions, means for resame, of an accelerating disk associated with said rotor, means for affording a normal driving connection between said accelerating disk and said driving element but permitting relative movement therebetween under predetermined conditions, a pawl pivoted in proximity to said disk and adapted to engage the same while restraining movement thereof, means associated with said disk and adapted to engage said pawl for automatically setting the latter in restraining osition, and means for releasing said paw to permit accelerated movement of the rotor.

- 18. In a device of the class described, the

combination with the rotor of a magneto,

and a driving element for actuating the same,.of an accelerating disk associated with said rotor, said disk being provided with a notch having a shoulder, means for afl'ording a normal driving connection between said accelerating disk and said driving ele- .ment but permitting relative movement disk and adapted to engage the shoulder of said notch for restraining movement of said disk, automatic means for actuating said pawl to engage, the same with said notch, andmeans for releasing said pawl from said notch to permit accelerated movement of the rotor.

19. In a device of the class described, the combination with the rotor of a magneto, and a driving element for actuating the same, of an accelerating disk associated with said rotor, said disk having a notch and a shoulder at one end thereof, means for affording a normal driving connection between said accelerating disk and said driving element but permitting relative movement therebetween under predetermined conditions, a pawl pivoted in proximity to said disk, the nose of said pawl being'provided with an inclined cont-actface adapted to engage the shoulder of said notch, whereby to hold the accelerating disk in restrained position, means associated with said disk for automatically setting said pawl in position to engage said shoulder, and means for releasing said pawl from engagement with said shoulder to permit accelerated movement of the rotor.

20 In a device of the class described, the combination with-the rotor of a magneto, and a driving element for actuating the same, of an accelerating disk associated with 1 said rotor,'said disk being provided with a notch having a shoulder at one of its ends, the peripheral face of said disk adjacent to said shoulder being inclined, means for affording a normal driving connection between said accelerating means and said driving element but permitting relative movement therebetween under predetermined conditions, a pawl pivotedin proximity to said disk, said pawl being provided with divergent inclined contact faces one of which is adapted to engage the shoulder of said notch at slow speed of the rotor to lock the disk in restrained position, the other contact face being engaged by the inclined face of said disk at high speed of the rotor, whereby to throw the pawl to non-restraining position, means associated with said disk pawl arranged in proximity to said accelerating means and adapted to restrain the movement of the latter, a plurality of mountings for said pawl, whereby the same may be reversely arranged with respect to said accelerating means, means for actuating said pawl to et the same in restraining position with respect to said accelerating means, and means for releasing said pawl to permit accelerated movement of said means.

22. In a device of the class described, the combination with the rotor of a magneto, and a driving element for actuating the same, of accelerating means associated withv said rotor, a supporting plate, a pivoted pawl associated with said supportingplate and cooperating with said accelerating means to lock the latter in restrained posltion, a

' plurality of mountings carried by said plate and with which said. :pawl may be interchangeably fitted, whereby to reverse the pawl with respect to said accelerating means, means for actuating said pawl to set the same'in restraining position, and means for and adapted to cooperate with said accelerating means to lock the latter in restrained position, a plurality of mountings for said pawl to which the same may be interchangeably fitted, whereby to reverse the pawl wlthrespect to said accelerating means, a plurality of perforated lugs also associated with said supporting plate, an arm carried by said pawl, a stem pivoted to said arm, and projecting through the perforated lug in proximity to the mounting to which said pawl is pivoted, a spring interposed between said lug and the arm of said pawl, whereby to hold the latter in restraining and nonrestraining position with respect to the accelerating means, means for actuating said pawl to set the same in restraining position, and means for releasing the pawl to permit accelerated movement of the rotor.

JOSEPH WOLFGANG HERMANN. 

